1. Aloise D, Deshpande A, Hansen P, Popat P (2009) NP-hardness of Euclidean sum-of-squares clustering. Mach Learn 75(2):245–248
2. Arthur D, Vassilvitskii S (2007) k-means++: The Advantages of Careful Seeding. In: Proceedings of the 18th annual ACM-SIAM symposium on discrete algorithms, pp 1027–1035
3. Äyrämö S, Kärkkäinen T (2006) Introduction to Partitioning-Based Clustering Methods with a Robust Example. Reports of the Department of Mathematical Information Technology Series C, Software engineering and computational intelligence 1/2006
4. Bachem O, Lucic M, Hassani H, Krause A (2016) Fast and Provably Good Seedings for K-means. In: Advances in neural information processing systems, pp 55–63
5. Bachem O, Lucic M, Krause A (2018) Scalable K-means Clustering via Lightweight Coresets. In: Proceedings of the 24th ACM SIGKDD international conference on knowledge discovery and data mining, pp 1119–1127